Mould King 26008 Great Ball Contraption Harp Track Building Kits, Harp Track Blocks Toys with XL Motor, Gift Toy for Kids Age 8+ /Adult Collections Enthusiasts(1508 Pieces)

For the most part this build comes together and works well, the value for this set is very good. But the problem is that there were two parts missing. The order page says they will replace parts, but they make it pretty difficult to actually do so. (they ask you to contact the vendor on Amazon, but there's no way to do that except to request a full refund). Ultimately, this is a great set, but if you get unlucky and are missing some key parts, it could be really annoying.EDIT: Someone from the company contacted me after this review, and sent me the missing parts. Changing my review to reflect that.

Works as it should, reasonable price.10/10

Had lots of fun putting this set together with my son but early on we realized it was missing a couple small gears, which are essential for operation. We completed the rest of the build and made sure that was all that was missing and it was, but there is no way to get those replacement gears without requesting a full refund and that seems like such a waste and would be lots of time to disassemble for return shipping.Update: Found the gears needed here (https://www.amazon.com/116-Technical-Gears-Axle-Connectors/dp/B09VC2F55Y/) and seller reimbursed me the cost so updating this from 2 to 4 stars. Would be better if it came with everything it needed but glad seller is so responsive to reviews on here.The instructions are good, though the part about the axle coupling between the drive shaft and blade assembly is finnicky and prone to popping off. Also needed to do some filing on all the orange pieces that make up the steps of the marble stairs.Regular player marbles up to 0.618" work better / more reliably than the included plastic marbles. Larger marbles tend to get stuck in one part or another, but may work if you're willing to invest more time in filing.

easy to use

Two pieces were missing in the set and after a week of using it, (it was a Christmas gift) the gears started to snap in half, completely making the whole thing useless. I can't find the seller contact information and the QR code on the packing takes me to a website that won't load. Super frustrating!